Healthy Waterways
High E.coli counts in the Annapolis River renew interest in the rivers health
After reporting bacteria levels in the Annapolis River exceeding what is considered safe for recreational use this summer, staff from an NGO whose goal is to improve the ecological health of the river have experienced a resurgence of interest in water quality of the historic waterway.
Clean Annapolis River Project said increased interest is not surprising, considering the summer saw significant promotion of recreational use of the Annapolis River, including the completion of new dock facilities at Riverside Park, Middleton, Jubilee Park, Bridgetown, and Annapolis Royal Causeway – plus events such as the Annapolis River Festival and the Bridgetown Triathlon.
CARP has been monitoring water quality on the Annapolis River since 1992 through the Annapolis River Guardians program. In addition to monitoring E. coli as an indicator of bacterial pollution, other parameters monitored include ph, temperature, dissolved oxygen, and turbidity. Eight sites are presently monitored on a biweekly basis between Aylesford and Bridgetown.
In a media release, CARP said that while the high E. coli levels may have come as a surprise for some, E. coli levels that exceed limits for recreational use are not atypical, particularly in dry summer months, when bacteria become concentrated as water levels drop.
Water Quality
Monitoring results are reported based on the Canadian Water Quality Guidelines, produced by the Canadian Council of Ministers of the Environment, the release said. E. coli concentration is the most commonly used indicator for fecal contamination in fresh water.
E. coli is a type of fecal coliform bacteria. While the vast majority of E. coli types are harmless, several may act as human pathogens. According to the CCME, a strong correlation has been demonstrated between the concentration of E. coli in fresh waters and the risk of gastrointestinal illness among swimmers.
E. coli bacteria results are reported in colony forming units (cfu) per 100 ml of water. Levels above 200 are considered unacceptable for direct human recreational contact. Guidelines for other uses include:
0 acceptable for drinking
1-50 acceptable for livestock watering
50-100 acceptable for food crop irrigation
100-200 unacceptable for human recreational contact (primary contact, eg. swimming)
Results
Results from samples taken July 25, 2017 ranged from 411 cfu/100 ml at the Paradise and Lawrencetown sites and 2419 cfu/100ml at the furthest upstream site in Aylesford.
Samples taken Sept. 5 showed 326 cfu/100 ml at Kingston with levels at two other sites between 100 and 200 cfu/100ml. The other five sites were below100 cfu/100ml.
There are many pathways for fecal coliforms to enter freshwater systems, said CARP, including runoff from manure, direct defecation by livestock with access to watercourses, unmaintained septic systems, straight pipes, or overflow from waste water treatment plants.
“Monitoring water quality is important not just as an alert system for human health risks, but to inform management decisions that impact water quality in the long term and to assess the impacts of different management options,” CARP said.
In recent years CARP has struggled to maintain the River Guardians water quality monitoring program, the release said. External grants tend to favour new, shortterm projects, despite the importance of maintaining a robust, long-term data set.
“CARP strongly believes that resources need to be dedicated to addressing the sources of water pollution,” said spokesperson Katie Mclean. “Examples of these activities include working with farmers to address issues related to agricultural run off and to fence livestock out of watercourses; working with landowners to create vegetated buffers and restore wetland habitats, which help to filter water pollution; and providing resources to support homeowners with the maintenance of septic systems.”